Int 10 Fn BF09  - Video - Compaq Extensions - Turn On Reverse Video        [b]

   AX = BF09h

Return: CF clear

Notes: sets bit 6 of port 03CEh index 81h; in some cases also sets index 84h
     to 6Fh and index 83h to 04h
   supported by at least the QVision board and the LTE Lite ROM BIOS

See Also: AX=BF0Ah,AX=BF0Bh